Drug and alcohol abuse by people with severe and persistent mental illness (SPMI) is one of the most significant problems facing the public mental health system. Despite extensive research on the problem, there is a dearth of empirical data on effective techniques for producing change, and no approach meets criteria for an evidence-based practice. We have been conducting a Stage lb project to develop a new treatment for dual disordered patients, and the preliminary outcome data suggest that the treatment is well accepted by patients and significantly reduces drug use. Based on these data, we now propose to conduct a larger, Stage 2 trial to evaluate the effects of BTSAS compared to STAR, a manualized treatment as usual that we developed for the current project. A major problem we encountered in our trial, which is common in both the clinical and research literatures, was low rates of engagement. We have developed a two-pronged intervention to increase engagement, and thereby widen the applicability of BTSAS. The approach involves: a) a Critical Time Intervention (CTI), a time-limited case management technique; and b) a psychoeducational intervention for Concerned Significant Others (CSOs)(family members, friends), that aims to enlist them as partners to help connect the patient with treatment. We propose to investigate the effects of this intervention for increasing engagement and treatment retention in BTSAS. A total of XXX SPMI patients who meet DSMIV criteria for dependence on cocaine, opioids, or cannabinoids will be randomly assigned to STAR, BTSAS, or BTSAS + CTI/CSO. The specific aims of this proposed project are to determine: 1) if BTSAS is more effective in reducing drug use than STAR, and 2) if CTI/CSO contributes to an increased rate of treatment engagement and a lower rate of attrition than BTSAS alone.